<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>混合框架结构</title>
</head>
<frameset rows="50%,50%">

  <frame src="frame_a.html">

  <frameset cols="25%,75%">
    <frame src="frame_b.html">
    <frame src="frame_c.html">
  </frameset>

</frameset>
<body>

</body>
</html>